Until she saw her baby, the mother would not eat, drink or move. She sat soaked and trembling, looking out across the Aegean for a rescue boat we knew wouldn’t come. Three hundred people had been on her boat when it sank. All night, we volunteers had been seeing in the rescue boats, providing urgent care and gathering names of the missing. We’d had reports that two newborns were flown to hospital in critical condition. Chances were that one of them was hers, but the police wouldn’t let us drive her to the hospital. Rescued at sea by the authorities, she was formally “in detention” until she registered. “No papers, no hospital,” they said.

Hours before, I’d performed CPR for the first time in my life, on a little boy who hadn’t survived. I was in shock too and haunted by the notion that this mother’s presence might somehow make the difference between life and death for her child. At the very least, she was being robbed of her chance to say goodbye. We sat shoulder to shoulder, in silence, with her relatives around her. “Where do you hope to go?” one of the other volunteers asked in a weak attempt to dent the silence. “To Britain,” a relative replied. “To live free.”

The refugee camps have always been there, swelling quietly with the very human consequences of the political system that governs our lives. But with the age of televised warfare, the lights came on. War is becoming real for us, for the first time in a long time. Here are its orphans, its exiled freedom fighters and grieving mothers, camping out right on our doorstep. Conflict, climate change, globalisation: it can’t be some grisly reality TV show after all; here are its refugees, real human families throwing themselves on the southern steps of Fortress Europe.

What happened next was extraordinary. There’s the side of the story we know: politicians scapegoating, talk of swarms and cockroaches in the press; a thundering Brexit vote followed by a spike in hate crime so sharp it gave the nation whiplash. But then there’s the other story, less often told: that well below the radar of the mainstream media, tens of thousands of people from all nations, of all ages, cultures and political persuasions, started giving up jobs, studies, relationships and reliable wifi and heading for the borderlands to do their part. They flooded in to do what politicians and aid agencies wouldn’t: from illegal ocean rescues and calling out police brutality to running art therapy classes, feeding thousands and sorting sky-high piles of donated clothes across the continent from Norway to Calais.

I feel enormously proud to have been part of that movement. I learned a lot as a solidarity volunteer in Greece. Some of those lessons were traumatic – I still have nightmares a year later – but I think I learned as much about politics in weeks in Camp Moria as I did in years at university. The most personally challenging and painful lesson was a simple one: it will never be enough. However many volunteers we have pulling 15-hour shifts, politicians in halls of power far away are doing more damage in a week than we could undo in a lifetime. For all their summits, resolutions and deals, in 2015 one in 269 people crossing to Europe died; this year it’s one in 88. With deprivation and incarceration systematically inflicted on people in the name of border control, when we say “refugees welcome” that is a commitment to campaign for radical change here at home – or it’s meaningless.

In December 2015 I was taken out of action by a serious spinal injury. Being forced home was infuriating. I started providing online support, fundraising, anything to fight the creeping sense of powerlessness, to stay connected. I started following the news again, watching in horror as governments closed the Balkan route and levelled camps at Calais and Dunkirk. Autonomous humanitarian aid was being criminalised, camps sealed off from independent observers and mass deportations introduced. Meanwhile, the EU-Turkey deal started edging “the refugee crisis” off our front pages; it was someone else’s problem now. Europe had paid a handsome price to make it so.

Coming home, it’s strange trying to figure out where you used to fit in. Media headlines about immigration stop being abstract and become about people we know. Apathy and discrimination start to hurt instead of just irritate because we’ve seen their casualties starving and cold and the empty orange lifejackets floating in the sea. We know what it costs. We’re not supposed to just fit back in when we come home. We’re supposed to be opening eyes. The fight for refugee and migrant rights out there can’t be won without a radical political shift here, in the heart of Fortress Europe.

The solidarity-based approach developed and demonstrated by the best of the independent volunteers has enormous potential to achieve this. It has the power, not just to save lives, but to change lives; to heal the divisions in our communities torn by politicians scapegoating the poor and the undocumented for a crisis they created.

It’s not about charity. It’s about recognising shared responsibility for the state of our shared world; understanding we have always been connected. By refusing to provide safe passage, refusing its fair share of refugees and detaining over 30,000 undocumented people every year, the British government is reinforcing the precedent that black and brown lives don’t matter. If that passes unchallenged, we are all forced into a more dangerous, divided and desolate world. And with states cracking down on independent solidarity work, simply saving lives is becoming a political act.

Humanitarian aid without a political movement is like trying to extinguish a forest fire with water one teacup at a time. Every time they raze Calais to the ground I am reminded of that painful truth.

One of the most urgent battles for asylum and immigration justice in the UK is against detention. This pointless, brutal practice is the most harmful aspect of the system. It cripples the ability of detainees to fight their own legal cases or speak out for justice. With a growing protest movement at detention centres such as Yarl’s Wood, ending detention is a fight we can win right here at home. That means everything from raising awareness to the direct action of the fearless grandmas who brought immigration raids to a halt in Glasgow. A movement that broad is ambitious; but ambition and vision are all that will stop our descent into barbarism.

Work that builds practical solidarity infrastructure and political resistance which work together, from the heartlands to the borderlands, outlines the way forward: projects such as These Walls Must Fall, which combines campaigning with a solidarity-based approach to migration and asylum support to empower those affected to fight back for their rights as part of our community. We’re taking on a multimillion-pound industry which profits from the system and has close ties to the government. But if we win, that victory would be felt well beyond our borders. If walls can fall in Fortress Britain – they can fall anywhere.